Al—Mg-based alloys are widely used in the fields of aviation, aerospace and transportation etc. The improvement of the strength and the corrosion resistance of the alloys has been the key issue of Al—Mg-based alloys research. Al—Mg alloys belong to non-heat-strengthened wrought aluminum alloy. The main methods for strengthening rely on magnesium (Mg) atom solid solution strengthening and cold-work hardening. The strength of Al—Mg alloys is improved with the increase of Mg content. However, when the mass percent of Mg exceeds 3.5%, age softening which lead the decrease of strength will occur during the long-term service as the decrease of the supersaturated Mg in the matrix even at room temperature, and Al—Mg alloys are easy to precipitate the beta phase (Mg2Al3) continuously along the grain boundaries to form the intergranular films which result in serious intergranular corrosion and stress corrosion. Cold-work hardening could improve the strength of the alloys mainly by cold working, but the greater the amount of cold deformation will be, the higher deformation energy will store, and the thermodynamics of the alloys is more unstable. Therefore stabilization annealing treatment must be carried out on the higher Mg content of cold deformed Al—Mg alloys to make its mechanical properties remain stable, and control the location and the distribution of beta phase to make the beta phase not continuously precipitate along the grain boundaries so as to improve the long-term resistance to intergranular corrosion of the alloys.
As the above two methods for strengthening are limited, the Al—Mg-based alloys are further researched and developed in order to meet the ever-increasing demands of the mechanical properties in the fields of ships and vessels, etc. The study indicated that the micro-alloying can effectively improve the mechanical properties of the alloys. Recent years' studies found that by adding trace Er into aluminum alloy, the grains can be refined, and finely dispersed precipitates which pin dislocations can be formed in the matrix, so as to increase the mechanical properties of the alloys.
The strength of Al—Mg-based alloys could be relatively high and stable, and their resistance to intergranular corrosion is good by the micro-alloying of Al—Mg-based alloys and the combination of the appropriate cold deformation and the stabilization annealing process. The excellent comprehensive performance of Al—Mg-based alloys can ensure the stabilization of the long-term operation and security during application process. There are many studies of the heat treatment process of the alloys such as 5052, 5754, 5083, especially the state of H116, H2N, and H3N. But the stabilization annealing process of the high-Mg Er-containing aluminum alloy plates of large cold deformation is rarely reported.